PIC12C509AT-04ESM View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC12C509AT-04ESM

8-Pin, 8-Bit CMOS Microcontrollers

Microchip Technology 

PIC12C5XX

COMF

Complement f

Syntax:

[ label ] COMF f,d

Operands:

0 ≤ f ≤ 31

d ∈ [0,1]

Operation:

(f) → (dest)

Status Affected: Z

Encoding:

0010 01df ffff

Description:

The contents of register ’f’ are comple-

mented. If ’d’ is 0 the result is stored in

the W register. If ’d’ is 1 the result is

stored back in register ’f’.

Words:

1

Cycles:

1

Example:

COMF REG1,0

Before Instruction

REG1 = 0x13

After Instruction

REG1 = 0x13

W

= 0xEC

DECF

Decrement f

Syntax:

[ label ] DECF f,d

Operands:

0 ≤ f ≤ 31

d ∈ [0,1]

Operation:

(f) – 1 → (dest)

Status Affected: Z

Encoding:

0000 11df ffff

Description:

Decrement register ’f’. If ’d’ is 0 the

result is stored in the W register. If ’d’ is

1 the result is stored back in register ’f’.

Words:

1

Cycles:

1

Example:

DECF CNT, 1

Before Instruction

CNT = 0x01

Z

=0

After Instruction

CNT = 0x00

Z

=1

DECFSZ

Decrement f, Skip if 0

Syntax:

[ label ] DECFSZ f,d

Operands:

0 ≤ f ≤ 31

d ∈ [0,1]

Operation:

(f) – 1 → d; skip if result = 0

Status Affected: None

Encoding:

0010 11df ffff

Description:

The contents of register ’f’ are decre-

mented. If ’d’ is 0 the result is placed in

the W register. If ’d’ is 1 the result is

placed back in register ’f’.

If the result is 0, the next instruction,

which is already fetched, is discarded

and an NOP is executed instead mak-

ing it a two cycle instruction.

Words:

1

Cycles:

1(2)

Example:

HERE

DECFSZ

GOTO

CONTINUE •

•

•

CNT, 1

LOOP

Before Instruction

PC

= address (HERE)

After Instruction

CNT =

if CNT =

PC

=

if CNT ≠

PC

=

CNT - 1;

0,

address (CONTINUE);

0,

address (HERE+1)

GOTO

Unconditional Branch

Syntax:

[ label ] GOTO k

Operands:

0 ≤ k ≤ 511

Operation:

k → PC<8:0>;

STATUS<6:5> → PC<10:9>

Status Affected: None

Encoding:

101k kkkk kkkk

Description:

GOTO is an unconditional branch. The

9-bit immediate value is loaded into PC

bits <8:0>. The upper bits of PC are

loaded from STATUS<6:5>. GOTO is a

two cycle instruction.

Words:

1

Cycles:

2

Example:

GOTO THERE

After Instruction

PC = address (THERE)

DS40139E-page 52

© 1999 Microchip Technology Inc.

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